1. Field of the Invention
The present invention relates to a method for controlling a respiratory gas source with a control unit, and to a breathing device.
2. Discussion of Background Information
Sleep disorders are generally due to obstructive sleep apnea (OSA), in which the respiratory flow is temporarily either significantly reduced (hypopnea) or fully interrupted (apnea). This oxygen deficit, however, is detrimental to restful sleep. Stress situations occur, which in the long and medium term can damage the heart. For this reason, patients with obstructive sleep apnea are additionally ventilated by sleep therapy devices or home breathing devices.
For the treatment of sleep apnea, there are different devices which can implement various therapies. One standard therapy is CPAP (continuous positive airway pressure) therapy, in which the breathing device applies a pressure elevated relative to atmospheric pressure to the patient. The patient breathes by himself The device thus only assists spontaneous respiration, the airways being opened by the continuous pressure.
A further therapy is APAP (automated positive airway pressure) therapy. In this case, the pressure is provided only during a respiratory problem (apnea or hypopnea). As an alternative, patients with periodic respiration or central apnea have to date been treated with devices which offer two different pressure levels, so-called bilevel devices. These devices provide two pressure levels, a higher inspiratory pressure (IPAP) and a lower expiratory pressure (EPAP). The pressure is provided only during periods which exhibit reduced or no spontaneous respiration. This way, the occurrence of oxygen saturation or arousal is prevented. If the patients are suffering from Cheyne-Stokes respiration, in which there is a periodic increase and decrease of the respiratory depth and of the spacing of the individual respiratory cycles, adaptive servoventilation is carried out as a form of therapy, in which the respiratory pressure is automatically regulated anticyclically in each respiratory cycle in order to induce stabilization of the respiration by variable pressure assistance.
These forms of therapy based on pressure monitoring contrast with volume-monitored therapy. In the case of volume compensation, a setpoint volume or target volume is specified, which the patient should reach so that he is ventilated sufficiently. The device respectively measures the patient's respiratory volume and increases the pressure to be administered, generally the inspiratory pressure, if the target volume is fallen below. Typical adjustment possibilities for such devices are the target volume, an interval for the inspiratory pressure and the regulation rate.
In view of the foregoing, it would be advantageous to have available an improved breathing device and a method for controlling a respiratory gas source, which ensures comfortable and robust breathing of a patient even in the event of complex illnesses.